He said: "When she met him for the first time, she was overwhelmed by intense feelings of love towards her co-accused.

"The usual taboos are not formed when siblings do not grow up together. That appears to be the situation with Ms Heaney. She is well aware her behaviour is unacceptable. She wants to have a relationship with her half-brother but she does not want to fall foul of the law again. "Her intention would be to have a non-sexual but loving relationship with her co-accused in the future."

Mr Sievwright added: "Neither of the accused would see themselves as victims. Both were willing partners in this activity."

Matthew Berlow, defending Cameron, said: "In no way does he seek to minimise his guilt."